Commit f9510fa9 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

jump_label, x86: Improve error when we fail expected text 



There is only a single usage site left, remove the function and extend
the print to include more information, like the expected text and the
patch type.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210506194157.726939027@infradead.org
parent e1aa35c4

arch/x86/kernel/jump_label.c

+14 −19
Original line number Diff line number Diff line
@@ -16,37 +16,32 @@ 
#include <asm/alternative.h>

#include <asm/text-patching.h>



static void bug_at(const void *ip, int line)

{

	/*

	 * The location is not an op that we were expecting.

	 * Something went wrong. Crash the box, as something could be

	 * corrupting the kernel.

	 */

	pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph) %d\n", ip, ip, ip, line);

	BUG();

}



static const void *

__jump_label_set_jump_code(struct jump_entry *entry, enum jump_label_type type)

{

	const void *expect, *code;

	const void *addr, *dest;

	int line;



	addr = (void *)jump_entry_code(entry);

	dest = (void *)jump_entry_target(entry);



	code = text_gen_insn(JMP32_INSN_OPCODE, addr, dest);



	if (type == JUMP_LABEL_JMP) {

		expect = x86_nops[5]; line = __LINE__;

	} else {

		expect = code; line = __LINE__;

	}

	if (type == JUMP_LABEL_JMP)

		expect = x86_nops[5];

	else

		expect = code;



	if (memcmp(addr, expect, JUMP_LABEL_NOP_SIZE))

		bug_at(addr, line);

	if (memcmp(addr, expect, JUMP_LABEL_NOP_SIZE)) {

		/*

		 * The location is not an op that we were expecting.

		 * Something went wrong. Crash the box, as something could be

		 * corrupting the kernel.

		 */

		pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph != %5ph)) type:%d\n",

				addr, addr, addr, expect, type);

		BUG();

	}



	if (type == JUMP_LABEL_NOP)

		code = x86_nops[5];